1. Field of the Invention
The present invention relates to a medical image processing apparatus, a medical image processing method, and a non-transitory computer readable medium storing a medical image processing program for specifying at least either vertebral bodies included in the vertebrae and intervertebral discs between the vertebral bodies in a medical image in which a plurality of vertebrae are included.
2. Description of the Related Art
The spinal cord serves to transmit messages between the brain and each part of the body, and is a very important part. Therefore, the spinal cord is protected by the spine that is formed by a plurality of vertebrae. In addition, damage to the vertebrae or the presence of a lesion in the vertebrae is checked for by interpreting tomographic images obtained by scanning a subject. In this case, for example, in order to specify a damaged vertebra or a vertebra with a lesion, it is necessary to recognize each vertebra. For this reason, various algorithms of vertebral segmentation, which is image processing for separating a plurality of vertebrae recognizably based on tomographic images and labeling each vertebra, have been proposed.
For example, U.S. Pat. No. 8,792,694B has proposed a method of segmenting the individual vertebrae by image recognition processing with a three-dimensional image obtained from tomographic images, such as computed tomography (CT) images or magnetic resonance imaging (MRI) images, as a target and automatically assigning numbers to other vertebrae when the user specifies the number of one vertebra. In the method disclosed in U.S. Pat. No. 8,792,694B, the assigned numbers are displayed so as to overlap the image. Accordingly, a mistake in the number of each vertebra is less likely to occur.
In addition, JP2011-131040A has proposed a method of generating sectional images of a surface crossing the central axis of each vertebra and a surface parallel to the central axis of each vertebra with a three-dimensional image as a target, calculating a feature amount indicating the sharpness of the sectional shape in each sectional image and a feature amount indicating the regularity of the arrangement of vertebrae, separating the vertebrae from each other by specifying the position of an intervertebral disc located between the vertebrae based on these feature amounts, and labeling a region of each of the separated vertebrae.
In Meelis Lootus, Timor Kadir, Andrew Zisserman: “Vertebrae Detection and Labelling in Lumbar MR Images”, MICCAI 2013, a method of specifying the vertebrae and the sacrum based on the relationship between adjacent candidates after finding candidates for the vertebral bodies and the sacrum using a discriminator that has learned the shape characteristics of the vertebral bodies included in the vertebrae has been proposed. In the method disclosed in Meelis Lootus, Timor Kadir, Andrew Zisserman: “Vertebrae Detection and Labelling in Lumbar MR Images”, MICCAI 2013, it is possible to assign a number to each vertebra based on the sacrum by estimating the sacrum.
In addition, JP2014-121598A has proposed a method of extracting a spinal region from a sagittal image of the spine, performing edge enhancement processing of the spinal region, and extracting an intervertebral disc region based on the result.